Where can I discuss with deep learning beginners?
I highly recommend to get a local peer group. Meetups might be a good way to get to know some people. As a student at university you also have a lot of other options like going to lectures, creating a student group, organizing a local AI event / hackathon, ...

If this is not possible for you, here is what you can do online:


Reddit: r/deeplearning seems to have a couple of discussions. r/MachineLearning is cool if you want to discuss super recent stuff, but I would not say it is beginner level.
Google+
Coursera: if you take one of their courses, you will see a forum for discussions